Furthermore, the invention relates to an aerator comprising an aeration element for introducing a gas into a liquid and with a mounting device for mounting the aeration element, in particular in a clarifying basin.
From AT 506 717 an aerator of the same class is known, by means of which gas bubbles are introduced into a clarifying basin or wastewater basin for the biological cleaning of wastewaters. In the gasification or aeration of wastewaters it is important that the supplied gaseous oxygen be supplied to the wastewaters in the form of fine gas bubbles, to create an exchange surface as large as possible between the gas bubbles and the wastewater. For this purpose, the aerator comprises a membrane having small openings, through which the air bubbles may be released to the wastewater. The membrane is fixed to the side portions of a plate-shaped base body with the help of locking elements in groove-shaped recesses. The base body comprises side portions that can be pushed outwards for the membrane together with the locking elements to be taken out of the clamping grooves.
Different aeration devices are described in CH 532 532 A, DE 196 45 781 C1, DE 88 07 929 U1 and EP 0 806 400 A1.
To mount the aeration device on the bottom of the clarifying basin, in the prior art the base plate is connected to a mounting plate on the bottom side. To this end, the base body comprises horizontal, inwardly projecting retaining flanges, which in the mounted state are engaged behind by corresponding cantilevers of the mounting plate. The mounting plate is screwed to the bottom of the clarifying basin on opposite sides. Basically, this mounting device functions reliably, however, it should be further improved.
Therefore, it is the object of the present invention to provide a mounting device of the above given type which has a simple construction and is inexpensive in manufacture, by means of which the mounting of the aeration element may be simplified further.
This object is solved by a mounting device for an aeration element for introducing a gas into a liquid, wherein the aeration element comprises a base body having at least one upwardly-projecting sidewall, wherein the mounting device comprises a mounting element for connecting to the sidewall of the base body of the aeration element, wherein the mounting element further comprises at least one elastically deflectable retaining web for detachably connecting to the at least one sidewall of the base body of the aeration element. Preferred embodiments are contained in the dependent claims.
In accordance with the invention the mounting element comprises at least one elastically deflectable retaining web for detachably connecting to the at least one sidewall of the base body of the aeration element.
In mounting the aeration element the retaining web can be pressed elastically outwards, in order to allow the arrangement of the aeration element in the mounting element. After completion of the loading, the retaining web returns to the initial or rest position due to its own elasticity, the aeration element being engaged positively within the mounting element. Accordingly, the base body of the aeration element and the retaining web of the mounting element can be connected to one another by a snap-fit assembly. As a result, the cost and effort of installation of the aeration element may be kept especially low. It is particularly preferred if the aeration element can be mounted between the retaining webs of the mounting element without any tools. Advantageously, it is also easily possible to remove the aeration element from the mounting element anchored in the clarifying basin. For this purpose, the retaining web of the mounting element can be pressed elastically outwards, whereupon the aeration element can be lifted out of the mounting element. Furthermore, it is advantageous that the elastically deformable retaining web involves a lower manufacturing effort than the mounting device provided in the prior art. In addition, the stability of the aerator may be increased.
To be able to connect the aeration element to the mounting device in a simple manner and, if necessary, remove it again from the mounting device, it is favorable that the mounting element has two retaining webs for detachably connecting to opposing sidewalls of the base body of the aeration element, wherein the two retaining webs are interconnected via a mounting portion that can be mounted in a clarifying basin. Accordingly, the mounting device can be mounted via the mounting portion in the clarifying basin, for example on the bottom of the clarifying basin or on a frame within the clarifying basin. Due to the flexible design of at least one of the retaining webs of the mounting element, the aeration element can be detachably mounted on the mounting device. For this purpose, the aeration element may initially be arranged in a tilted intermediate position in the mounting element, whereupon the aeration element can be pressed into its operating position. By contact with the base body, the associated retaining web is resiliently pivoted outwards from the initial position until the aeration element slides into the mounted operating position. Then, the deformed retaining web returns to its initial position, whereby the aeration element is fixed in the mounting element. In this embodiment, for this reason, the transition areas between the mounting portion and the retaining webs are formed as joints, which allow deflection of the retaining webs. To remove the aeration element from the mounting device, at least one of the retaining webs of the mounting element is deformed elastically to such an extent that the connection between the base body of the aeration element and the mounting element is released. It is also advantageous in this embodiment that, in the mounted operating state, the aeration element is held particularly stable between the opposed retaining webs of the mounting element.
To fix the aeration element, for one thing, in a transverse direction and, for the other, in a vertical direction in the mounted operating state, it is advantageous if the retaining web has a limiting portion for disposition on an outer surface of the sidewall and at least one retaining portion projecting inwardly from the limiting portion. With respect to the mounted operating state, the limiting portion is preferably arranged essentially vertically. The retaining portion is preferably arranged at an angle to the limiting portion. With respect to the mounted operating state, the retaining portion is preferably arranged essentially horizontally. The base body of the aeration element is held laterally by the limiting portion in the mounted operating state. The retaining portion also causes that the aeration element is secured against a corresponding vertical displacement in the mounted operating state. On the other hand, it is favorable if the limiting and retaining portions of the retaining web are adapted to allow a shift of the aeration element in its longitudinal direction. Preferably, the retaining web of the mounting element rests at least partially on the base body of the aeration element, so that for shifting of the aeration element the frictional engagement between the mounting element and the aeration element is overcome. Advantageously, thus the longitudinal position of the aeration element within the clarifying basin or wastewater basin easily can be adjusted.
To block any mobility of the aeration element in the mounted operating state, both upwards and downwards, it is advantageous if the retaining web has an upper and a lower retaining portion. The upper and lower retaining portions cooperate with corresponding edges of the aerator base body to fix the aeration element in the transverse direction, i. e. laterally as well as in the vertical direction.
According to a preferred embodiment it is provided that the lower retaining portion is connected to the mounting portion via a connecting portion preferably extending substantially in parallel to the limiting portion. Therefore, in this embodiment, the lower retaining portion is disposed above the mounting portion, connecting the opposite retaining webs of the mounting element to one another. A bulge is formed in the retaining web by the upper and lower retaining portions, in which bulge the sidewall of the base body of the aeration element can be arranged.
According to an alternative embodiment it is provided that the lower retaining portion is designed as a region of the mounting portion. In this embodiment, in the mounted operating state, the sidewall of the aeration element is held between the upper retaining portion and the lateral portion of the mounting portion of the mounting element.
For reasons of production, it is particularly favorable when the mounting element is formed as a one-piece profile part. This embodiment distinguishes itself by low production costs. The profile part has a cross-sectional shape staying constant in the longitudinal direction of the aeration element. Preferably, the profile part is made of steel. Alternatively, it may be provided as a plastic or fiber-reinforced plastic.
To facilitate disassembly of the aeration element, it is advantageous if the retaining web is connected at the free end to a grip element for deflecting the retaining web. For disassembly of the aeration element, the grip element can be grasped to bend the associated retaining web to the outside, so that the aeration element can be removed from the mounting device.
Moreover, for reasons of stability it is favorable when the grip element and the retaining web are designed integrally. Thereby, also the manufacturing costs can be kept low.
According to an embodiment which is particularly easy to produce, the grip element can be arranged in the same plane as the limiting portion of the retaining web. In this embodiment the grip element forms a continuation or extension of the limiting portion of the retaining web.
With respect to the manufacturing expenses, it is particularly favorable if the grip element comprises a recess which is preferably formed according to the upper retaining portion. In this way, in the production the retaining portion may be formed out of the grip element. For this purpose, cutting and bending lines may be provided in the mounting element to design the upper retaining portion. In production, initially a cutting line may be produced in a base material for the for the grip element, whereupon a portion of the grip element adjacent thereto can be bent to form the upper retaining portion.
In a preferred embodiment, the recess of the grip element is limited in sections by an edge between the upper retaining portion and the limiting portion of the retaining web. In this embodiment, in the mounted state, the upper retaining portion lies flat against the upper side of the sidewall of the aeration element. Preferably, the upper retaining portion is essentially semi-circular or trapezoidal. In this embodiment, the cutting line may correspond to the limiting line of the essentially semi-circular or trapezoidal upper retaining portion.
In another embodiment which is particularly easy to produce, the grip element has a substantially straight cutting line, wherein a portion of the grip element adjacent thereto is bent inwardly to form the upper retaining portion. In this embodiment, in the mounted state, the upper retaining portion rests on the upper side of the sidewall of the aeration element via its lower edge. The lower edge of the upper retaining portion preferably has a substantially semicircular or trapezoidal shape. A clearance preferably extending in a horizontal plane may be formed between the lower edge of the retaining portion and the substantially straight cutting line on the grip element, which clearance is connected to the recess of the grip element, which recess is formed in accordance with the retaining portion and preferably extends in a vertical plane.
Accordingly, the retaining web may comprise a further recess, which is shaped according to the lower retaining portion of the retaining web.
To facilitate handling of the mounting device during the assembly of the aeration element, it is advantageous if the grip element is preferably angled outwardly from the limiting portion of the retaining web.
In addition, due to the configuration of the mounting element it is possible that the mounting portion may comprise one, preferably exactly one mounting opening for arranging a mounting means. As compared to the prior art, the number of the mounting elements may be advantageously reduced.
To be able to adapt the arrangement of the aeration element within the clarifying basin with little effort, it is advantageous if the base body of the aeration element is arranged displaceably in a longitudinal direction between the retaining webs of the mounting element. Therefore, for displacing the aeration element, it is preferably only necessary to overcome the frictional engagement between the mounting element and the aeration element.
According to a preferred embodiment, the base body comprises a clamping groove in a lateral edge region for clamping a membrane element with passage openings for the gas, wherein the clamping groove is limited on the outside by the sidewall.